With her feelings regarding humanity and the purpose of Parasytes now in question, Reiko encounters Shinichi and Migi one final time. When police arrive on the scene, Shinichi soon finds himself at the center of their attention.
Migi says that Kana can emit a rather weak signal to other parasites so they can also seek her out. Shinichi tells her the truth while Migi is sleeping but things go unexpectedly.
A violent confrontation with a gang brings Shinichi face-to-face with a girl named Kana, who begins to take an interest in him. Shinichi's parents continue their vacation, but their trip is cut short by an unexpected attack.
The confrontation between Yuko and Hideo comes to a gruesome head when Hideo goes on a rampage throughout the school. With Satomi missing, Shinichi must hurry and find her before Hideo can get to her first.
The police commence their operation to take out Hirokawa and the remaining Parasytes. However, plans go awry when the Parasytes attempt to fight back. Things take an even more gruesome turn when Gotou appears on the scene.
Shinichi sets out for revenge and runs into an unexpected ally. Together they team up to take down the Parasyte that brutally attacked Shinichi's family. But when Migi falls asleep, Shinichi is forced to engage the enemy on his own.
With Shinichi at the brink of death, Migi takes drastic actions to ensure his host's survival. After a trying recovery, Shinichi learns that his father is still alive and races to his side before the Parasyte that attacked his mother strikes again.